Numerous adaptive braking and traction control systems have been provided previously. It is advantageous to provide a combination adaptive braking and traction control system which can be implemented in a vehicle as an add-on feature to the standard braking system. The adaptive braking and traction control system must be compatible with a standard master cylinder, while providing both adaptive braking and traction control functions. Some accumulator supplied adaptive braking systems require that a regulator valve meter the high pressure accumulator supply provided to the brakes through the modulator valves during cycling. The regulator keeps the supply pressure equal to the applied master cylinder pressure. Some traction control systems also require a supply valve to meter the accumulator pressure supplied to the modulators during traction control cycling. Such a valve typically provides a high pressure level without a master cylinder pressure being applied to the valve. It may be desirable to limit this traction control pressure to a set maximum level. It would be highly advantageous to combine both the adaptive braking and traction control systems and the related supply valves so that both functions could be provided by the same valve. This can lead to reduced components and complexity for the system, while reducing the internal circuits of the hydraulic assembly.